Container sealing ring



8, 1957 w. L. ELLIS 3,334,776

CONTAINER SEALING RING Filed Oct. 1, 1965 INVENTOR.

United States Patent 3,334,776 CONTAINER SEALING RING Warren Lincoln Ellis, Naperville, Ill., assignor to American Can Company, New York, N.Y., a corporation of New Jersey Filed Oct. 1, 1965, Ser. No. 491,963 8 Claims. (Cl. 220-53) The present invention. relates to sealing rings for containers and more particularly to a pull-open sealing ring formed from plastic tape and having an improved lap joint. Conventional sealing rings of this general type, too frequently leak in and around the lap joint and therefore posed a serious problem to packers using them. Therefore, an object of this invention is to provide a plastic tape sealing ring wherein the lap joint is leakproof.

Another object of the invention is the provision of a notched portion in a central part of the end of the inner layer of the lap joint to increase the length of edge sealing contact of this layer with the outer layer of the lap joint and also with surfaces of the container and closure adjacent their juncture which is sealed by the ring.

Still another object of the invention is the provision of a serpentine or serrated formation along the length of the notched portion of the inner layer of the lap to further increase the length of the above mentioned edge sealing contacts and provide greater security against leakage.

Yet another object of the present invention is the provision of a tearing tab on the outer layer of the lap joint whereby the ring may be broken quickly and removed from its container.

Other objects and advantages of the invention will be apparent as it becomes better understood from the following description which, when read in connection with the accompanying drawings, discloses a preferred embodiment of the invention.

Referring to the drawings:

FIG. 1 is a perspective view of a slip cover container provided with a pull tape ring embodying the instant invention;

FIG. 2 is an enlarged sectional view taken substantially along line 22 in FIG. 1;

FIG. 3 is an enlarged fragmentary view of the lap joint with a portion broken away for clarity of illustration;

FIG. 4 is a sectional view of the lap joint taken substantially along line 44 in FIG. 3; and

FIG. 5 is a sectional view taken substantially along line 55 in FIG. 3.

As shown in FIG. 1, in a preferred or exemplary embodiment a pull-open ring 11 extends around a container body 12 and a skirt 13 of a slip closure 14 at the juncture 16 between the container body and closure skirt. The body may be provided with a necked-in portion 18 (FIG. 2) so that the outer surfaces of the body 12 and closure skirt 13 may be flush and that the ring may lie smoothly in sealing engagement over the juncture 16.

The ring 11 may be formed from a tape or strip of plastic material 21 that is coated on its inner surface with an adhesive 22 and is overlapped adjacent its ends to form a lap joint 23. A pull tab 24 may be formed from the outer end of the tape extending beyond the outer layer 26 of the lap joint 23 to provide a quick or easy opening feature for the ring 11.

The inner layer 27 of the lap seam is formed with a notched central portion 28 extending inwardly from the inner end of the tape. This notched portion 28 is preferably formed with a serpentine or serrated edge 31 providing projections or teeth 32 which increase the effective axially oriented polyethylene terephthalate such as thatsold commercially by E. I. du Pont de Nem-ours & Co.

under the trade name Mylar.

The adhesive at 22 is preferably one having high shear strengh and low peel. One material with these properties is a compound having as its principal constituent polyvinylacetate ethylene copolymer and known as Elvax.

The ring 11 thus formed may be preformed and of a size which may be easily slipped over the juncture 16 between container body and cover, and then be shrunken and sealed in position by application of heat. On the other hand, a flat strip of tape, adhesive side inwardly, may be wound circumferentially around the containers at and including the juncture of the body 12 and skirt 13. In either case, the portion of the outer tape bridging the notch 28 is pressed inwardly to adhere directly to the substrate metal. The free end of this tape strip (except for a small portion to provide a pull tab 24) is then adhered to the opposite end of the tape in a lap joint to form the ring 11.

The tape seal of the instant invention will maintain hermeticity within the can whether the can body 12 is seamless or it has a longitudinal side seam. With side seamed can bodies it is preferred to increase the thickness of the layer of adhesive 22 to provide, in effect, caulking of the step at the seam.

The consumer may quickly unseal such a package by pulling on the tab 24, which breaks the vacuum thereby loosening the cover 14 for easy manual removal. The telescoping or slipover relationship between the body 12 and cover 14 permits ready reclosing of the can during its useful life.

It is thought that the invention and many of its attendant advantages will be understood from the foregoing description, and it will be apparent that various changes may be made in the form, construction and arrangement of the parts without departing from the spirit and scope of the invention.

I claim:

1. A container sealing ring of plastic tape having a lap joint, the inner layer of said lap joint being adhesively secured to the outer layer thereof and formed with a notched portion extending inwardly from a central part of the inner end of the tape to form a leakproof lap joint.

2. A sealing ring as set forth in claim 1 wherein the ring is formed of shrinkable plastic material and its inner surface is coated with a thermoplastic, non-tacky adhesive whereby the ring may be shrunken onto a container and its cover, and heat sealed thereon to hermetically seal the container.

3. A sealing ring as set forth in claim 1 wherein said notched portion is formed with a serpentine edge.

4. A sealing ring as set forth in claim 1 wherein said notched portion is formed with a serrated edge.

5. A sealing ring as set forth in claim 1 wherein said joint is presealed to provide a preformed ring ready for application to a container and its cover.

6. A sealing ring as set forth in cliam 5 wherein the ring is formed of shrinkable plastic tape slightly larger in internal dimensions than the external dimensions around the juncture of the container and cover whereby the ring is adapted to be disposed around and shrunken 3 onto areas of container and cover adjacent said juncture to seal the container.

7. In a container sealing ring of plastic tape adhered along one edge to the body of a container and along the other edge to the closure of said container for uniting said container and closure and for providing an hermetic seal therebetween, a lap joint in said tape, the inner layer of said lap joint being adhesively secured to the outer layer thereof and formed with a notched portion extending inwardly from the inner end of the tape, said notched portion having a serpentine edge to form a leakproof joint.

8. The container sealing ring set forth in claim 7 wherein a portion of the tape extends beyond the outer layer of the joint and provides a pull tab whereby said outer layer of the joint may be pulled and separated from said notched inner layer thereof to break and remove the ring from its sealing position.

References Cited UNITED STATES PATENTS THERON E. CONDON, Primary Examiner.

G. T. HALL, Assistant Examiner. 

1. A CONTAINER SEALING RING OF PLASTIC TAPE HAVING A LAP JOINT, THE INNER LAYER OF SAID LAP JOINT BEING ADHESIVELY SECURED TO THE OUTER LAYER THEREOF AND FORMED WITH A NOTCHED PORTION EXTENDING INWARDLY FROM A CENTRAL PART OF THE INNER END OF THE TAPE TO FORM A LEAKPROOF LAP JOINT. 